Intercepting-valve.



No. 888,375. PATENTED MAY 19, 1908. G. E. WILSON & W. J. FRAWLEY".

VINTBRCEPIING VALVE.

APPLICATION FILED FEB. 6l 1906.

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No. 888,375. PATENTED MAY 19, 1908. G. E. WILSON & W. J. PRAWLEY.

INTBRGBPTING VALVE.

APPLICATION FILED PEB. 6, 1906.

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GWW HQE riff/H @rra/swf YJ UNITED sTATEs PATENT oEEioE.`

GEORGE E. WILSON AND WILLIAM J. FRAWLEY, OF STILLWATER, MINNESOTA.

rN'nE'RcEPTING-VALVE.

Speccation of LettesPatent.

Patented May 19, 1908.

f Application med February e, isos. serial No. 299,801.

To all whom .it may concern: y

Washington county, Minnesota, lhave invented certain new and useful Improvements y in Interce ting-Valves for Cross-Compound Tractionngines, of which the following is a specification.

Our invention relates to traction engines', and particularly to those of the cross-compound type, and the object of the invention 1s to provide a compound traction enginel which will be economical oi fuel and Water, have a weight t an the ordinary traction engine, and be 'capable of exerting an even, steady pull on the load as compared with the uneven engine is automatically changed from a double-simple to a compound engine in starting?.l that 1s, the engine starts as a doublesimple, and without any attention on the part of the operator is almost instantly changed to a compound.

Further, the invention consists in various constructions and combinations, all as hereinater described and partidularly pointed out in the'claims.

In the accom anying drawings forming part of this s eci cation, Figure 1 is a transverse vertica sectional view of a crosscom pound traction engine and boilerembodyin our invention. Fig. 2 is a detail sectiona view illustrat' the intercepting valve in position to admit live steam to the low ressure cylinder. Fig. 8 is a plan section s 10W.- ing the valve in the'same position. a sectional View corresponding to Fig. 2 showing the position assumed by a valve when the pressure in the steam chest of the low pressure cylinder is one-third that of the boiler ressure. Fig. 5 is a detail sectional View s owing the valve which controls the exhaust from the high pressure cylinder in position to direct the exhaust to the stack.

In the drawing, 2 represents a live steam pipe having a suitable throttle valve 3 opreater power in proportion to its;

rig. 4 is.

erated by a mechanism l(not shown) within Be it known that we, GEORGE E. WILso'N and WILLIAM J. FRAWLEY, of Stillwater,I

convenient reach ofthe operator, and a-governor 4', through which the steam is conducted to a transversely arranged pi e- 5.

One end o f'this pipe 5 is connected wit the steam chest of the high pressure cylinder 7, the entrance of steam to said cylindergbeing controlled b the usual slide valve 8. The

opposite en of thepipe 5 is connected with a casing 9 havin achamber 10, which communicates with t epipe 54 through a passage 11 and with the steam chest 12 ofthe low pressure cylinder 13Y through a assage he areas of these cylinders are 1n the ratio approximatel of one to th'ree. `A valve 15 is provided within the chamber 10, havin va stem 16 at one end of less diameter than t e main portion of the valve, and located, when lthe valve is open, between the passages 11 and 14 to permit the live steam to How there.- through into the low pressure steam chest and'cylinder. A branch passage 17 leads from the passage 14 to a-point near the end wall of the chamber 10 to conduct the steam into the space between said end wall and the valve 15. The area of the valve end contiguous `to said wall is in this case about three times that of the opposite end of the valve with the cross sectional area of the stem, 16 deducted, or,in other words, the end ysurfaces of the 'valve exposed to the steam are in the ratio of three to one, corresponding substantially to the difference in area of the low and high. pressure cylinders. When, therefore, the pressure in the steam chest of the low pressure cylinder Ais about one-third thatof the boiler pressure, the intercepting valve will be moved 1b the pressure on its larger end toward the eft and cut off the passage of live steam to the low pressure cylinder;

this movement being due to the difference in` We prefer to connect the valve stem with gine.

being turned downwardly and carried through the wall of the fire box 25 and connected to one end of a super-heater` 26 lo cated above the grates,y and which forms the subject matter of a companion application for U. S. Letters Patent of'even date herewith Serial No. 299,803. This super-heater consists of a hollow casting arranged` transversely of the fire box, and connected at its opposite end from the pipes 23 with a similar pipe 27, which also extends throughjthe wall of the ire box, and is connected with the steam chest 12 of the low pressure cylinder. This steam chest communicates through ports similar to thoseleading to the high pressure cylinder, with a passage 28 leading to a pipe 29 which extends forward t0 the boiler stack.

The three-Way valve 22- is shown in IFig. -1 in its normal position, and when the throttle valve is opened and steam admitted to the pipe 5 it will` low down into the high pressure cylinder and across the engine to the chamber 10 andthe intercepting valve, and through the assage 14 to the low pressure chest and cy nder; and the engine 1n startin will bea double-simple, and thereby the ful ower of both cylinders can be utilized on t e initial movement. As soon, however, as the pressure, in the low pressure cylinder chest is equal to one-third the boiler pressure, the intercepting valve will be automatically lrnoved from the position shown in Figs. 2

and 3 to the position shown in F i e, the pressure of the steam on the end of t e valve 15 vexposed to the branch passage 17, and the steam in the low pressure steam chest having overcome the pressure of the steam on the opposite end, which is exposed to the steam in the live steam pipe., As soon as this valve has been moved across the passage 14 and shut olf the flow of live steam to the low pressure cylinder, the exhaust from the high pressure cylinder will flow down through the pipe 23 and across the fire box to the steam chest off the low pressure cylinder; and` the engine will then operate as a compound, being automatically changed from a doublesimpie without any eort or attention on the part of the operator. This change from a double-simple to compound will take place almost instantly after the starting of the en- The -interoepting valve will remain closed to the live steam, and the engine will operateas a compound as long as the pressure in the steam chest' of 4the low pressure cylinder does not fall below one-third of the boiler pressure.

in the practical operation ofthe engine the valve wil be closed nearly all of the time.

essere In case, however, the pressure in the 'low pressure cylinder steam chest falls below onethird boiler ressure, the intercepting valve will instanty open and admit live steanr enough to raise the pressure to the required ratio, and then instantly close a ain. valve lthus automatically adjusts itself without any attention to the variations of steam pressure, and maintains a constant fixed ratio between the ressure in the high and low pressure cylin ers. When it is desired to increase the draft for the purpose of quickening the iire, or for any other reason, the three-way valve 22 maybe operated to close the exhaust leading to the low pressure cylinder and open the passage to the pipe 24 andthe stack. -When this is done the engine becomes a doublesimple instead of a com-y pound, and maybe operated that way if preferred. Generally, however, the valve 22 will be in the position shown in Fig. 1, the pipel to the stack being closed and the engine used as a double-simple for a moment only in starting, and then automatically changed to a com ound. The intercepting valve enables t e full power of both cylinders to be utilized in starting, and then automatically shuts olf the live steam from the low pressure cylinder as soon as it is not needed. lt allows the engine to be operated as a doublesimple instead of a compound, and by automatically regulating the pressure in the low pressure cylinder prevents unequal distribution of the load on the two cranks. ,lt also insures s ufhcient pressure in the low pressure cylinder whenever running as a compound. The valve is absolutely automatic, and no attention is required on the part of the oper-v ator in running the engine, except to open and close the throttle.

We have shown the exhaust pine from the high pressure cylinder carried through the re box to the low pressure steam chest, but do not wish to coniine ourselves to this arrangement, as the intercepting valve will perform all of its functions if the pipe connectio'n between the cylinders is located outside of the ire box. in other ways the detail construction of the apparatus may be mddified without departing from our invention.

W e claim as our invention:

i. in a cross-compound traction engine, the combination, with a live steam pipe havn in a throttle valve, of high and low pressure cy inders having a steam passage le, anintercepting valve located between saidlive steam pipe and said low pressure chestand passage le and normally admitting live steam to said chest simultaneously with its admission to said high pressure steam chest, said valve having surfaces of different areas, the smaller surface being normally exposed to the live steam entering from said pipe and said passage le having a lay-pass l? leadingy The ils

essere to said larger surface, whereby upon the entrance ol live steam to said passage 14 and saidlow pressure steam chest, said interceptin/ valve will be instantly and automatica ly operated to close the live steam passa e ythrou` h said valve to said low pressure c est, an, the exhaust of said high pressure cylinder having a pipe communicating with the low pressure steam chest, whereby `upon the closing oi' said valve after the initial operation of the engine, the high ressure cylinder exhaust will be conducted) to the low pressure cylinder, substantially as described;

2. The combination, with a traction engine boiler, 0i high and low pressure cylinders mounted thereon and having steam chests and valves therefor, apipe extending transversely of said cylinders and above the same and communicating at one end with said high pressure steam chest and at its opposite end with said low pressure steam c est, a live steam pipe having a throttle valve communicating with said transverse pipe, an intercepting valve located in the passage leading from said transverse pipe to said low ressure steam chest and normally admitting ive steam to-said low pressure steam chest simultaneously with its admission to said high pressure steam chest, said valve having surfaces of different area exposed when the valve is o en to the live steam pressure and whereby t e said valve will be automatically closed when the pressure in the low pressure steam chest equals a predetermined ratio of the boiler pressure and said high pressure steam chest having an exhaust opening and a pipe communicating therewith and extending transversely of saidboiler and leading into i said low pressure steam chest, and -a second pipe also communicating with said high pressure exhaust and extending forward to the engine stack', and a three-way valve located between said high pressure exhaust opening and said pipes and arranged to direct the exhaust from said high ressure cylinder into one or the other of sai pipes, 'whereby the engine can be operated continuously as a compoundl or as a double simple, substantially as described.

In `witness whereof, we have hereunto set our hands this th day of January 1906. GEGRGE E. WILSON.

WlLLlAlll J. FRWJEY. llVitnesses:

S. BLAIR MCBEATH,

T. J. TAZENDIN. 

